We have studied the magnetoimpedance of micron sized magnetic tunnel junction sensors with 1.7 nm MgO tunnel barrier. We performed ac impedance spectroscopy in the frequency range between 100 Hz–40 MHz as a function of applied magnetic field in the sensing direction. We model our devices with a simple RLC circuit. Fitting the model to our data results in frequency independent , , and , and our low frequency results are in agreement with dc measurements. Despite excellent agreement with published result on interface capacitance for MgO barrier magnetic tunnel junctions similar to ours we do not observe any magnetocapacitance in our devices.
REFERENCES
1.
D.
Mazumdar
, W.
Shen
, X.
Liu
, B.
Schrag
, M.
Carter
, and G.
Xiao
, J. Appl. Phys.
103
, 113911
(2008
).2.
C.
Chappert
, A.
Fert
, and F. N. V.
Dau
, Nature Mater.
6
, 813
(2007
).3.
W.
Shen
, X.
Liu
, D.
Mazumdar
, and G.
Xiao
, Appl. Phys. Lett.
86
, 253901
(2005
).4.
G.
Landry
, Y.
Dong
, J.
Du
, X.
Xiang
, and J.
Xiao
, Appl. Phys. Lett.
78
, 501
(2001
).5.
M.
Gillies
, A.
Kuiper
, R.
Coehoorn
, and J.
Donkers
, J. Appl. Phys.
88
, 429
(2000
).6.
H.
Kaiju
, S.
Fujita
, T.
Morozumi
, and K.
Shiiki
, J. Appl. Phys.
91
, 7430
(2002
).7.
W.
Chien
, C.
Lo
, L.
Hsieh
, Y.
Yao
, X.
Han
, Z.
Zeng
, T.
Peng
, and P.
Lin
, Appl. Phys. Lett.
89
, 202515
(2006
).8.
P.
Padhan
, P.
LeClair
, A.
Gupta
, K.
Tsunekawa
, and D.
Djayaprawira
, Appl. Phys. Lett.
90
, 142105
(2007
).9.
J.
Huang
, C.
Hsu
, W.
Chen
, and Y.
Lee
, IEEE Trans. Magn.
43
, 911
(2007
).10.
K.
McCarthy
, A.
Hebard
, and S.
Arnason
, Phys. Rev. Lett.
90
, 117201
(2003
).11.
K.
McCarthy
, S.
Arnason
, and A.
Hebard
, Appl. Phys. Lett.
74
, 302
(1999
).12.
X.
Liu
, D.
Mazumdar
, W.
Shen
, B.
Schrag
, and G.
Xiao
, Appl. Phys. Lett.
89
, 023504
(2006
).13.
S.
Chui
and L.
Hu
, Appl. Phys. Lett.
80
, 273
(2002
).14.
S.
Zhang
, Phys. Rev. Lett.
83
, 640
(1999
).15.
16.
H.
Miesenböck
and M.
Tosi
, Z. Phys. B: Condens. Matter
78
, 255
(1990
).17.
B.
Schrag
, A.
Anguelouch
, S.
Ingvarsson
, and G.
Xiao
, Appl. Phys. Lett.
77
, 2373
(2000
).© 2010 American Institute of Physics.
2010
American Institute of Physics
You do not currently have access to this content.